Optical disc and disc cartridge

ABSTRACT

An optical disc and a disc cartridge for accommodating the optical disc, wherein the disc cartridge accommodates a disc non-symmetrical in cross-section relative to the center of thickness of the disc, in which disc cartridge includes a main cartridge body portion and an opening/closure mechanism. The main cartridge body portion has an aperture via which to insert or take out the disc. The main cartridge body portion is configured for accommodating the disc only in the regular state of the disc which permits recording and/or reproduction of the disc. The opening/closure mechanism opens or closes the aperture.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates to an optical disc and a disc cartridge. Moreparticularly, it relates to an optical disc and a disc cartridgeemploying two disc substrates.

2. Description of the Related Art

Recently, in keeping up with the increasing recording density ofinformation signals, a sole bonded optical disc, in which two discsubstrates for optical discs, such as compact discs (CDs), ormagneto-optical discs, each formed by a single disc substrate, arebonded together to form a single disc. This bonded disc is composed oftwo disc substrates of the same design specifications with the signalrecording surfaces facing to the outside. The signal recording surfacesare formed on the front and back sides of the bonded disc.

Among the bonded optical discs, there are such discs in which a signalrecording layer is formed only on one disc substrate, while the otherdisc substrate performs the role of assuring the mechanical strength ofthe first disc substrate. The bonded optical disc is housed within thedisc cartridge for recording and/or reproducing information signals by arecording/reproducing apparatus.

This disc cartridge is comprised of a main body portion made up of apair of cartridge halves, namely an upper cartridge half and a lowercartridge half, each in the shape of a shallow saucer, abutted andbonded to each other.

Within the interior of the main cartridge body portion is formed a dischousing section, larger in thickness than the optical disc and alsolarger in size than the outer size of the disc, delimited by anarcuate-shaped upstanding wall member. The disc is housed rotatablywithin the disc housing section.

In the upper and lower surfaces of the main cartridge body portion areformed recording and/or reproducing apertures extending from a centerportion towards the front side at a mid portion in the left-and-rightdirection of the main cartridge body portion. These recording and/orreproducing apertures permit a portion of the recording area of the dischoused within the main cartridge body portion to be exposed to theoutside.

On the main cartridge body portion is slidably mounted a shuttergenerally substantially U-shaped in cross-section. The shutter iscomprised of a pair of shutter portions dimensioned to close therecording and/or reproducing apertures and a connecting portioninterconnecting the shutter portion. This shutter closes the recordingand/or reproducing apertures only when the disc cartridge is loaded onthe recording and/or reproducing apparatus, while otherwise opening therecording and/or reproducing apertures. When out of use, the shutterprevents the dust and dirt from entering the inside of the maincartridge body portion while preventing the user's hand or fingers fromtouching the recording area of the disc.

The above-described bonded optical disc suffers from an inconveniencethat, when the disc substrates are registered and bonded to each otherin this state in the production process, there is produced a deviationin the relative positions of the disc substrates.

By this position deviation, produced at the time of bonding, theportions of inner dimensions E1, E2 of the center apertures of two discsubstrates 420A, 420B represent an inner dimension E3 of the centeraperture of a bonded optical disc 420. The result is the inconveniencethat the offset of the outer dimension relative to the center aperturesis increased if, for bonding the disc substrates 420A, 420B to eachother, a reference shaft of a centering jig is passed through the centerapertures of the disc substrates 420A, 420B for positioning.

When the bonded optical disc 420 is housed within a disc housing section422 of a disc cartridge 421, as shown in FIG. 3, there is raised aproblem that difficulties are encountered in assuring a clearancenecessary between the inner peripheral wall section of the disc housingsection 422 and the outer rim of the bonded optical disc 420.

In a disc cartridge, there are occasions wherein a double sided disc, inwhich a recording area ID provided on each side of the disc substratefor increasing the disc capacity so that both the front and back sidesof the disc substrate perform the role ob the recording and/orreproducing surfaces, is housed therein. It has been proposed toconstruct the disc cartridge housing the disc so that the disc can beinserted into or ejected from the cartridge.

The disc cartridge is constructed so that, when recording and/orreproduction of the information signals on one of the recording surfacesthereof comes to a close, the disc cartridge is ejected once from theapparatus, reversed upside-down and re-inserted via a cartridgeinsertion aperture of the recording and/or reproducing apparatus.

With the above-described disc cartridge, having housed therein the discfor recording and/or reproduction, if recording and/or reproductioncomes to a close and the next disc is recorded and/or reproduced, a newdisc has to be exchanged for the disc for which recording and/orreproduction has come to a close. Since the disc is constructed to havethe same outer size, it is difficult for the user to discern the desiredrecording and/or reproducing surface, such that the disc tends to behoused within the disc cartridge in the incorrect condition.

For example, if the disc is housed in the disc cartridge with therecording and/or reproducing side other than the desired side set to thereproducing side, and the disc cartridge is loaded in this state on therecording and/or reproducing apparatus for recording/reproduction, itmay occur that the required information signals be inadvertently erased.

SUMMARY OF THE INVENTION

It is therefore an object of the present invention to provide an opticaldisc which resolves the above-described problem.

It is another object of the present invention to provide a disccartridge which resolves the above-described problem.

An optical disc according to the present invention includes first andsecond disc substrates. The first disc substrate has a recording layerand is formed with a first center aperture. The second disc substratehas a recording layer and is formed with a second center aperture. Thesecond disc substrate is bonded to the first disc substrate so that therespective recording layers face each other. The first center apertureor the second center aperture is larger in diameter than the remainingcenter aperture.

An optical disc according to the present invention includes first andsecond disc substrates. The first disc substrate has a reflective layerand is formed with a first center aperture. The second disc substratehas a reflective layer and is formed with a second center aperture. Thesecond disc substrate is bonded to the first disc substrate so that therespective reflective layers face each other. The first center apertureor the second center aperture is larger in diameter than the remainingcenter aperture.

A disc cartridge according to the present invention accommodates thereina disc produced on bonding two disc substrates together. The disc isnon-symmetrical in cross-sectional shape relative to the bonding surfaceas center. The disc cartridge includes a main cartridge body portion andan opening/closure mechanism. The main cartridge body portion has anaperture via which to insert or take out the disc and is configured foraccommodating the disc only in the regular state of permitting recordingand/or reproduction to the disc. The opening/closure mechanism opens orcloses the aperture.

A disc cartridge according to the present invention accommodates a discthat is non-symmetrical in cross-section relative to the center ofthickness of the disc. The disc cartridge includes a main cartridge bodyportion and an opening/closure mechanism. The main cartridge bodyportion has an aperture via which to insert or take out the disc and isconfigured for accommodating the disc only in the regular state ofpermitting recording and/or reproduction to the disc. Theopening/closure mechanism opens or closes the aperture.

A disc cartridge according to the present invention includes a maincartridge body portion, an opening/closure mechanism and a takeoutinhibiting mechanism. The opening/closure mechanism opens or closes theaperture. The opening/closure movement of the opening/closure mechanismis inhibited when the inhibiting mechanism specifics the state ofinhibiting recording on the disc. The takeout inhibiting mechanismspecifies whether or not recording on the disc is possible and inhibitstakeout of the disc from the main cartridge body portion in therecording inhibiting state. The takeout inhibiting mechanism is providedon the main cartridge body portion.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view showing an arrangement of a bonded opticaldisc.

FIG. 2 is a cross-sectional view of an optical disc shown in FIG. 1.

FIG. 3 is a cross-sectional view showing the state in which the opticaldisc shown in FIG. 1 is housed within a cartridge.

FIG. 4 is a perspective view showing an arrangement of an optical discaccording to a first embodiment of the present invention.

FIG. 5 is a cross-sectional view of the optical disc shown in FIG. 4.

FIG. 6 is a perspective view showing an arrangement of an optical discaccording to a second embodiment of the present invention.

FIG. 7 is a cross-sectional view of an optical disc shown in FIG. 6.

FIG. 8 illustrates the state in which two disc substrates of the opticaldisc of the second embodiment are bonded together.

FIG. 9 is a perspective view showing an arrangement of a disc cartridgehousing the first embodiment of the optical disc therein.

FIG. 10 is a perspective view showing the state in which the disccartridge shown in FIG. 9 is seen from its reverse side.

FIG. 11 is a perspective view showing the state in which an optical discis inserted into the disc cartridge shown in FIG. 9.

FIG. 12 is across-sectional view showing the state in which the opticaldisc shown in FIG. 9 is housed within a cartridge.

FIG. 13 is a schematic perspective view showing a mistaken recordinginhibiting mechanism of the disc cartridge shown in FIG. 9.

FIG. 14 is a perspective view showing an optical disc and a disccartridge according to a third embodiment of the present invention.

FIG. 15 is a cross-sectional view showing the state in which an opticaldisc has been housed in the disc cartridge according to the thirdembodiment of the present invention.

FIG. 16 is a perspective view showing an optical disc and a disccartridge according to a fourth embodiment of the present invention.

FIG. 17 is a cross-sectional view showing the state in which an opticaldisc has been housed in the disc cartridge according to the fourthembodiment of the present invention.

FIG. 18 is a perspective view showing a disc cartridge according to afifth embodiment of the present invention.

FIG. 19 is a cross-sectional view showing the state in which an opticaldisc has been correctly housed within a disc cartridge according to thefifth embodiment of the present invention.

FIG. 20 is a cross-sectional view showing the state in which the opticaldisc has been housed in an incorrect state in the disc cartridgeaccording to the fifth embodiment of the present invention.

FIG. 21 is a schematic perspective view showing a mistaken recordinginhibiting mechanism for a disc cartridge according to a sixthembodiment of the present invention.

FIG. 22 is a schematic perspective view showing a mistaken recordinginhibiting mechanism for a disc cartridge according to a seventhembodiment of the present invention.

FIG. 23 is a schematic perspective view showing a mistaken recordinginhibiting mechanism for a disc cartridge according to an eighthembodiment of the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring to the drawings, an optical disc and a disc cartridgeaccording to the present invention will be explained in detail.

First, an optical disc according to the present invention is explained.

An optical disc 1 according to a first embodiment of the presentinvention is comprised of a first disc substrate 1A and a second discsubstrate 1B bonded to the first disc substrate 1A, as shown in FIGS. 4and 5.

The first disc substrate 1A is formed as a disc having a center aperture1D of a light-transmitting synthetic resin or the like material. Thisfirst disc substrate 1A has an annular signal recording area S which iscovered by a reflective layer as a recording layer formed of, forexample, aluminum, and a protective layer of a synthetic resin, such asa UV curable resin. The protective layer is formed for covering theupper surface of the reflective layer for overlying one of the majorsurfaces in its entirety. If the optical disc 1 is a read-only opticaldisc, the reflective layer is formed of, for example, aluminum. However,if the optical disc is a recordable disc, it is formed of an opticalrecording material.

The second disc substrate 1B is formed as a disc having a centeraperture 1E of a synthetic resin, such as polycarbonate resin. By beingbonded to the first disc substrate 1A, the second disc substrate 1Boperates as a supporting plate for maintaining mechanical strength ofthe first disc substrate 1A. Similarly to the first disc substrate 1A,the second disc substrate 1B may be provided with a reflective layer anda protective layer. In this case, the second disc substrate 1B is bondedto the first disc substrate 1A so that the respective reflective orprotective layers face each other.

The second disc substrate 1B is formed so that its center aperture willhave an inner dimension D3 larger than the inner dimension D1 of thecenter aperture 1D of the disc substrate 1A and an outer dimension D4smaller than the outer dimension D2 of the disc substrate 1A. Theoptical disc 1 is formed on its outer periphery with a step 1C, as shownin FIG. 4.

The second disc substrate 1B is designed so that the value by which theinner dimension of the center aperture 1E thereof is larger than that ofthe first disc substrate 1A or the value by which the outer diameter ofthe second optical disc is smaller than that of the first optical disc1A will be equal to or larger than any position deviation produced onbonding.

In the above-described optical disc 1, the state in which the first discsubstrate 1A and the second disc substrate 1B are bonded together isexplained. First, a reference shaft of a centering jig is insertedthrough center apertures 1D, 1E of the first disc substrate 1A and thesecond disc substrate 1B, respectively, for positioning. Afterpositioning relative to each other, the first disc substrate 1A and thesecond disc substrate 1B are bonded together using a UV curableadhesive. The UV curable adhesive is pre-coated on at least one of themajor surfaces of the first or second disc substrate. After relativepositioning, mentioned above, the UV rays are irradiated from the seconddisc substrate side for solidifying the UV curable adhesive.

With the above-described optical disc 1 according to the firstembodiment, since the inner dimension D1 of the center aperture of thefirst disc substrate 1A is smaller than the inner dimension of thecenter aperture of the second disc substrate 1B, while the outerdimension D2 of the first disc substrate 1A is larger than the outerdimension of the first disc substrate 1A, it becomes possible to preventthe position deviation from being produced during bonding. A centeraperture 1F of the optical disc 1, thus formed, must be the centeraperture 1D of the disc substrate 1A.

With the present optical disc 1, the inner dimension D1 of the centeraperture 1D may be positively prevented from becoming smaller than theinner dimensions D1 or D3 of the center aperture 1E of the second discsubstrate 1B, while the outer dimension D2 of the center aperture 1D maybe positively prevented from becoming larger than the outer dimensionD2, D4 of the second disc substrate 1B.

With the present optical disc 1, it becomes possible to provide anecessary clearance between the outer rim of the disc and the inner wallsection of the disc housing section of the disc cartridge as laterexplained.

An optical disc 2 according to a second embodiment of the presentinvention is comprised of a first disc substrate 2A and a second discsubstrate 2B bonded to the first disc substrate 2A, as shown in FIGS. 6and 7.

The first disc substrate 2A is formed as a disc having a center aperture2D of a light-transmitting synthetic resin, such as polycarbonate resin.This first disc substrate 2A has an annular signal recording area Swhich is covered by a reflective layer as a recording layer formed of,for example, aluminum, and a protective layer of a synthetic resin, suchas a UV curable resin. The protective layer is formed for covering theupper surface of the reflective layer for overlying one of the majorsurfaces of the first disc substrate 2A in its entirety. If the opticaldisc 2 is a recordable optical disc, a recording layer formed of anoptical recording material is provided in place of the A1 reflectivelayer.

The second disc substrate 2B is formed as a disc having a centeraperture of a synthetic resin, such as polycarbonate resin. By beingbonded to the first disc substrate 2A, the second disc substrate 2Boperates as a supporting plate for maintaining mechanical strength ofthe first disc substrate 2A. The second disc substrate 2B may beprovided with a reflective layer and a protective layer, as in the firstembodiment described above. In this case, the second disc substrate 2Bis bonded to the first disc substrate 2A so that the respectivereflective or protective layers face each other.

The second disc substrate 2B is formed so that its center aperture willhave an inner dimension D7 larger than the inner dimension D5 of thecenter aperture 2D of the disc substrate 2A and an outer dimension D8larger than the outer dimension D6 of the disc substrate 2A. The opticaldisc 2 is formed on its outer periphery with a step 2C, as shown in FIG.7.

In the above-described optical disc 2, the state in which the first discsubstrate 2A and the second disc substrate 2B are bonded together isexplained. First, a reference shaft of a centering jig, not shown, isinserted through a center apertures 2D of the first disc substrate 2Afor positioning the outer dimension of the second disc substrate 2B withthe center aperture 2D of the first disc substrate 2A as reference.After relative positioning, the first disc substrate 2A and the seconddisc substrate 2B are bonded together using a UV curable adhesive.

With the above-described optical disc 2 according to the secondembodiment, since the inner dimension D7 of the center aperture 2E ofthe second disc substrate 2B is larger than the inner dimension D5 ofthe center aperture 2D of the first disc substrate 2A, while the outerdimension D8 of the second disc substrate 2A is larger than the outerdimension D6 of the first disc substrate 2A, it becomes possible tomaintain an offset of the outer dimension relative to the innerdimension of the second disc substrate 2B so as to be equivalent to orbetter than the offset of the outer dimension relative to the innerdimension of the center aperture 2F of the first disc substrate 2A. Theresult is that the center aperture 2F of the optical disc 2 must be thecenter aperture 2D of the first disc substrate 2A.

Thus, with the first disc substrate 2A, it is unnecessary to maintainoffset of the inner dimension of the center aperture to the outerdimension with high accuracy, while it is unnecessary with the seconddisc substrate 2B to maintain offset of the outer dimension to the innerdimension of the center aperture. The result is that, with the opticaldisc 2, the first disc substrate 2A and the second disc substrate 2B canbe manufactured with relative ease, thus reducing the production cost.

With the present optical disc 2, it becomes possible to provide anecessary clearance between the outer rim of the disc and the inner wallsection of the disc housing section of the disc cartridge as laterexplained, thus enabling a disc cartridge to be produced at a reducedcost.

In addition, with the present optical disc 2, the offset between thecenter aperture 2D of the first disc substrate 2A having the signalrecording area S and the outer rim of the optical disc 2 can bemaintained with high accuracy, so that it becomes possible to set theclearance necessary between the inner wall section of the disc housingsection of the disc cartridge as later explained and the outer rim ofthe disc 2 to a small value. Thus it is unnecessary with the presentoptical disc 2 to maintain high precision on the side of therecording/reproducing apparatus to reduce the production cost of therecording and/or reproducing apparatus.

Next, a disc cartridge according to the present invention, housingtherein an optical disc according to the above-described firstembodiment, is explained.

Referring to FIGS. 9 and 10, a disc cartridge 10 has a main cartridgebody portion 14 which is made up of an upper cartridge half 12 and alower cartridge half 13 each of which is shaped as a saucer of shallowdepth. The optical disc 1 is rotatably accommodated within the maincartridge body portion 14. A shutter 16 is slidably mounted on the frontside of the main cartridge body portion 14. In the back side of the maincartridge body portion 14 is formed a disc insertion/takeout aperture,not shown in FIGS. 9 and 10, via which the disc 1 can be inserted ortaken out. The optical disc 1 herein is an optical disc capable ofrecording information signals.

The upper cartridge half 12 and the lower cartridge half 13 are eachformed of a synthetic resin material of good moldability and sufficientmechanical strength, such as ABS resin, substantially in the shape of asaucer of shallow depth, as shown in FIGS. 9 and 10. The upper and lowercartridge halves 12, 13 are formed with upstanding peripheral wallsections 21a, 21b, respectively. These wall sections are formed on theperipheral portions of the cartridge halves except the rear lateralsides. When the upper and lower cartridge halves 12, 13 are combinedtogether, the upstanding peripheral wall sections 21a, 21b are abuttedagainst each other and secured together by plural set screws for makingup the outer peripheral wall section of the main cartridge body portion14.

On each of the facing inner surfaces of the upper and lower cartridgehalves 12, 13 are formed plural interrupted arcuate wall sections lyingon the same circumference of a circle for inscribing the peripheral wallsections 21a, 21b. These arcuate wall sections together make up a dischousing wall section 19. The disc housing wall section 19 of the uppercartridge half 12 is slightly larger than the outer diameter of the discsubstrate 1B and larger in height than the thickness of the discsubstrate 1B. The disc housing wall section 19 of the lower cartridgehalf 13 is slightly larger than the outer diameter of the disc substrate1A and larger in height than the thickness of the disc substrate 1A.When the upper and lower cartridge halves 12, 13 are combined together,the disc housing wall sections 19 make up the disc housing section 20along with the inner surfaces of the cartridge halves 12, 13. This dischousing section 20 delimits a spacing slightly larger than the outershape of the optical disc 1 and substantially convex-shaped incross-section. The disc housing section 20 restricts movement of theoptical disc 1 housed in the inside of the cartridge main body portion14.

In the cartridge halves 12, 13 are formed apertures 22, 23,respectively, extending from the center portions towards one lateralsides of the cartridge halves 12, 13. Into mid portions 22a, 23a of theapertures 22, 23 is intruded a disc table of the recording and/orreproducing apparatus when the disc cartridge 10 is loaded thereon. Thedisc table is configured for rotationally driving the optical disc 1housed within the disc housing section 20.

In continuation to the mid portions 22a, 23a of the apertures 22, 23 areextended portions 22b, 23b located towards one lateral sides of thecartridge halves 12, 13. These portions 22b, 23b permit at least part ofthe recording area 14 of the optical disc 1 to be exposed to the outsideacross the inner and outer rims of the disc. These portions 22b, 23b areused as recording and/or reproducing apertures 23. That is, when thedisc cartridge 1 is loaded on the recording and/or reproducingapparatus, a recording/reproducing unit, such as an optical head, facesthe optical disc 1 via these portions 22b, 23b of the apertures 22, 23.

In the outer surface of the main cartridge body portion 14 is formed arecess 26. The recess 26 is formed in register with the movement rangeof the shutter 16 which is moved between a position of closing theapertures 22, 23 and a position of opening the apertures 22, 23 by ashutter opening/closure mechanism provided on the recording and/orreproducing apparatus when the disc cartridge 10 is loaded thereon.

When the disc cartridge 10 is not in use, that is, when the disccartridge 10 is not loaded on the recording and/or reproducingapparatus, the shutter 16 prevents dust and dirt from entering the dischousing unit 20 via the apertures 22, 23 so as to be deposited on theoptical disc 1 housed within the disc housing unit 20. When in the stateof closing the apertures 22, 23, the shutter 16 prevents the hand orfinger from touching the recording area S of the disc 1. The shutter 16is produced by press-working a thin metallic plate and is comprised of apair of major surface sections 28a, 28b dimensioned to close theapertures 22, 23 of the upper and lower cartridge halves 12, 13 and aconnecting portion 29 interconnecting these major surface sections 28a,28b. The shutter 16 is formed so as to have a U-shaped cross-section.

The shutter 16 is secured by plural set screws to a shutter guidemember, not shown. In both lateral sides of the connection portion 29 ofthe shutter 16 are formed cut-outs 31a, 31b into which are intrudedshutter opening pins of a shutter opening/closing mechanism, not shownof the recording and/or reproducing apparatus.

The above-described shutter 16 is mounted in the recess 26 of the maincartridge body portion 14 for clamping the main cartridge body portion14. The distal ends of the major surface sections 28 are pressed by ashutter retainer member 34, while a shutter guide member, not shown, isfitted in a mating guide groove formed in the main cartridge bodyportion 4. The disc cartridge 10 is retained by an end of a spring, notshown, the other end of which is retained by the main cartridge bodyportion 4. The shutter 16 is perpetually biased by this spring in adirection indicated by arrow A in FIG. 9. When the shutter 16 is loadedon the recording and/or reproducing apparatus, the shutter opening pinof the shutter opening mechanism is engaged with one of the cut-outs 31aor 31b. This causes the shutter to be slid in a direction indicated byarrow B in FIG. 9 from a position closing the apertures 22, 23 to aposition opening the apertures 22, 23.

Although the above description has been made of the shutter member 16being moved in one direction, the shutter member 16 may, of course, beconstructed so as to be moved in the left-and-right direction. In thiscase, the recess 16 in the main cartridge body portion 14 needs to beformed in the entire area on the forward side of each of the uppercartridge half 12 and the lower cartridge half 13.

Towards the front side on both lateral side edges of the main cartridgebody portion 14 are formed insertion control recesses 36a, 36b. Theseinsertion control recesses 36a, 36b are engaged by insertion controlpins on an automatic loading device when the disc cartridge 10 isautomatically loaded by the automatic loading device on the recordingand/or reproducing apparatus. The insertion control recesses 36a, 36bare engaged by insertion control pins on the automatic loading devicewhen the disc cartridge 10 is moved by the automatic loading device asfar as a pre-set position in the recording and/or reproducing apparatus.

The insertion control recesses 36a, 36b are formed for extending fromthe upper cartridge half 12 through to the lower cartridge half 13.Since the insertion control recesses 36a, 36b are formed through theentire thickness of the disc cartridge, it can be discerned, when theplural disc cartridges 10 are housed in the stacked state in the disccartridge housing device, whether the disc cartridges 10 are housed inthe regular orientation. If the disc cartridges 10 are not housed in theregular orientation, the insertion control recesses 36a, 36b are notaligned with one another, thus allowing the user to discern which of thedisc cartridges has been housed in the incorrect orientation.

Towards the rear side on both lateral side edges of the main cartridgebody portion 14 are formed takeout control cut-outs 37a, 37b. When thedisc cartridge 10 is taken out automatically from the recording and/orreproducing apparatus, these takeout control cut-outs 37a, 37b areengaged by takeout pins, not shown, provided on the automatic loadingdevice. When the disc cartridge 10 is moved from the pre-set position inrecording and/or reproducing apparatus by the automatic loading device,the takeout control cut-outs 37a, 37b are engaged by the takeout pinsprovided on the automatic loading device.

These takeout control cut-outs 37a, 37b are not formed from the uppercartridge half 12 through to the lower cartridge half 13, but are formedfrom the lower cartridge half 13 as far as a mid height level of theupstanding peripheral wall section 21 of the upper cartridge half 12.Thus, when the disc cartridge 10 is taken manually out of the discrecording and/or reproducing apparatus, that is, without using theautomatic loading device, these takeout control cut-outs 37a, 37b arenot caught by the peripheral wall portion of the disc cartridgeinsertion opening of the disc recording and/or reproducing apparatus,thus enabling smooth insertion or ejection.

In the main cartridge body portion 14, there is formed, on the sidethereof opposite to the side carrying the shutter 16, a discinsertion/ejection aperture 17, as shown for example in FIG. 11. Whenthe disc cartridge is, not in use, that is when the disc cartridge isnot loaded on the disc recording and/or reproducing apparatus, the discinsertion/ejection aperture 17 is closed by a lid 40 mounted on a hingeon the rear side of the main cartridge body portion 14 foropening/closure with respect to the main cartridge body portion 14.

On both lateral sides of the disc insertion/ejection aperture 17 of theupper cartridge half 12 are formed rib-like retainers 41. By theprovision of the retainers 41, the disc insertion/ejection aperture 17is formed so as to be larger in size than the cross-sectional area ofthe optical disc 1 as a whole and is opened in the shape of a rectanglestepped at each upper edge. The disc insertion/ejection aperture 17 ismade up of a first opening 17a delimited by the retainers 41 in registerwith a step 1C of the optical disc 1 and having the size of the longside slightly larger than the diameter of the disc substrate 1B with asmaller diameter and the size of the short side slightly larger than thethickness of the disc substrate 1B, and a second opening 17b having thesize of the long side slightly larger than the diameter of the discsubstrate 1A with a larger diameter and the size of the short sideslightly larger than the thickness of the disc substrate 1A.

The disc insertion/ejection aperture 17, constructed as described above,is kept in communication with the inside and the outside of the maincartridge body portion 14 and with the disc housing section 20 in themain cartridge body portion 14. This prevents the optical disc 1 frombeing inserted in a mistaken manner into the disc housing section 20 viathe disc insertion/ejection aperture 17. When inserting the optical disc1 into the disc housing section 20, such insertion of the optical disc 1is enabled only when the optical disc is inserted via the discinsertion/ejection aperture 17 with the substrate 1B of the optical disc1 in alignment with the first aperture 17a and with the substrate 1A ofthe optical disc 1 in alignment with the second aperture 17b.Conversely, should the optical disc 1 be inserted into the discinsertion/ejection aperture 17 with the substrate 1A of the optical disc1 in alignment with the first aperture 17a and with the substrate 1B ofthe optical disc 1 in alignment with the second aperture 17b, the step1C of the optical disc 1 is abutted against the retainers 41 thusinhibiting insertion of the optical disc 1 into the inside of the dischousing section 20.

The lid 40, adapted for closing the disc insertion/ejection aperture 17,has a main portion 45 for closing the disc insertion/ejection aperture17, a hinge portion 46 formed at an end of the main portion 45, and aretention piece 47 formed at the opposite end of the main portion 45.

The main portion 45 has a closure surface 48 facing the discinsertion/ejection aperture 17. The closure surface 48 has a thicknesssubstantially equal to the height of the disc insertion/ejectionaperture 17 of the main cartridge body portion 14 and a length at leastsubstantially equal to the length of the disc insertion/ejectionaperture 17 and is dimensioned to be large enough to close the discinsertion/ejection aperture 17. Thus, when in the state of closing thedisc insertion/ejection aperture 17, the main portion 45 is flush withthe major surface and lateral side of the main cartridge body portion14.

The hinge portion 46 supports the main portion 45 for opening/closurewith respect to the main cartridge body portion 14 by having a fittingportion, not shown, on the main portion 45, fitted on a supporting pin,not shown, formed on one end of the disc insertion/ejection aperture 17of the main cartridge body portion 14. On the opposite end of the mainportion 45 is formed a retention piece 47 as one with the main portion45. The distal end of the retention piece 47 is formed as a retainer 49.

When in the state of closing the disc insertion/ejection aperture 17,the lid 40 is engaged with a protrusion, not shown, formed on theopposite end of the disc insertion/ejection aperture 17 of the maincartridge body portion 14, so that it is not opened even if subjected tovibrations during transport of the disc cartridge 10. When opening thedisc insertion/ejection aperture 17, the lid 40 is disengaged from theprotrusion, not shown, of the retention piece 47, so as to be opened ina direction shown by arrow C in FIG. 11.

The main cartridge body portion 14, as shown in FIG. 13, is providedwith a mistaken recording inhibiting mechanism 50 configured forpreventing inadvertent erasure of information signals recorded on theoptical disc 1. This mistaken recording inhibiting mechanism 50 is madeup of a mistaken recording inhibiting member 51, arranged in thevicinity of a corner of the main cartridge body portion 14 towards thedisc insertion/ejection aperture 17, and a control opening 52 formed inthe main cartridge body portion 14 for exposing the inhibiting member 51to the outside.

The mistaken recording inhibiting member 51 is made up of an operatingportion 53 exposed to the outside of the control opening 52 and aretention portion 54 for retaining the optical disc 1, and is formed inits entirety of a synthetic resin material in a U-shaped cross-section.The control opening 52 is formed in the vicinity of the corner of theupper and lower cartridge halves 12, 13 towards the discinsertion/ejection aperture 17.

When the mistaken recording inhibiting mechanism 50 is in the firstposition, that is, in a position indicated X in FIG. 13, the retentionportion 54 of the mistaken recording inhibiting member 51 retains thelateral edge of the disc 1, while allowing for intrusion of a detectionportion of mistaken recording detection means, not shown, provided onthe recording and/or reproducing apparatus, thus inhibiting writing ofnew information signals. When in the first position, that is, in theposition X shown in FIG. 13, the mistaken recording inhibiting member 51inhibits extraction of the disc 1 from the disc insertion/takeoutaperture 17, while simultaneously inhibiting writing of new informationsignals on the disc 1.

When the mistaken recording inhibiting member 51 is slid to a secondposition, that is, a position indicated Y in FIG. 13, the mistakenrecording inhibiting mechanism 50 is released from the state in whichthe retention portion 54 retains the lateral edge of the disc 1. Thisenables the optical disc 1 to be taken out of the disc insertion/takeoutaperture 17, while inhibiting intrusion of the mistaken recordingdetection means, not shown, provided on the recording and/or reproducingapparatus, thus permitting recording of new information signals. When inthe second position, that is, in the position shown at Y in FIG. 13, themistaken recording inhibiting member 51 enables the optical disc 1 to betaken out of the disc insertion/takeout aperture 17, while permittingrecording of new information signals.

If the above-described disc cartridge 10, having the optical disc 1housed therein, is loaded on the recording and/or reproducing apparatus,the disc cartridge 10 is positioned by a positioning mechanism, notshown, while the shutter 16 is slid in a direction indicated by arrow Bin FIG. 9 for exposing the apertures 22, 23 to the outside. The opticaldisc 1 housed in the disc cartridge 10 is clamped by the disc table onthe recording and/or reproducing apparatus and by the chuck member andthereby enabled for rotation.

With the above-described disc cartridge 10, when the disc 1 is taken outof the optical disc cartridge 10, the mistaken recording inhibitingmember 51 of the mistaken recording inhibiting mechanism 50 is broughtsimultaneously to the second position, that is to the position Y shownin FIG. 13. Thus the user may be apprized of the fact that the writingon the exposed optical disc 1 is enabled. If the optical disc 1 isloaded on the recording and/or reproducing apparatus in the state inwhich it is not accommodated within the disc cartridge 10, newinformation signals can be written on the optical disc 1.

Also, with the disc cartridge 10, if the optical disc 1 is accommodatedin the disc cartridge 10, and the mistaken recording inhibiting member51 of the mistaken recording inhibiting mechanism 50 is, in the firstposition, that is in the position X shown in FIG. 13, the user may beapprized of the fact that writing on the optical disc 1 is disabled.

If the above-described disc cartridge 10 is loaded on the recordingand/or reproducing apparatus in the state in which the optical disc 1 isaccommodated therein, the disc cartridge 10 is positioned, at the sametime as the shutter 16 is moved in a direction indicated by arrow B inFIG. 9, thus exposing the apertures 22, 23 to the outside.

The disc table on the recording and/or reproducing apparatus is intrudedinto the inside of the recording and/or reproducing apparatus via one ofthe mid portions 22a, 23a of the apertures 22, 23. The optical disc 1accommodated within the disc cartridge 10 is clamped by the chuck memberand the disc table provided on the recording and/or reproducingapparatus and thereby enabled for rotation.

The optical disc housed within the disc cartridge 10 can be exchangedwith a new one when the disc cartridge is not in use. In this case, withthe lid 40 of the disc cartridge 10 opened and with the discinsertion/takeout aperture 17 facing to the outside, the disc cartridgeis tilted, with the aperture 17 facing downwards. The optical disc 1 canbe slid and taken outwards. For accommodating the optical disc 1 in themain cartridge body portion 14, the side of the optical disc 1 towardsthe disc substrate 1B is set towards the first aperture 17a, while theside of the disc 1 towards the disc substrate 1A is set towards thesecond aperture 17b, with the lid 40 in the closed state. The opticaldisc 1 is inserted in this state via the disc insertion/takeout aperture17. Since the disc insertion/ejection aperture 17 is formed so as to belarger in size than the cross-sectional area of the optical disc 1 as awhole and is opened in the shape of a rectangle stepped at each upperedge, in register with the step 1C of the optical disc 1, there is norisk of the optical disc 1 being inserted upside-down.

Therefore, with the present disc cartridge 10, there is no risk of theuser inadvertently inserting the optical disc 1 into the main cartridgebody portion 14, with the recording and/or reproducing side not desiredto be recorded or reproduced set in the recording and/or reproducingposition, while there is also no risk of inadvertent erasure of thedesired information signals recorded on the optical disc 1.

In the above-described disc cartridge 10, it is assumed that the dischousing section 20 formed in the main cartridge body portion 14 is inthe shape of a rectangle stepped at each upper edge, similar to theshape of the disc insertion/takeout aperture 17. It should however benoted that the disc housing wall sections of the upper and lowercartridge halves 12, 13 can be slightly larger than the outside diameterof the disc substrate 1A for delimiting a disc housing section with arectangular cross-section.

An optical disc and a disc cartridge according to a third embodiment arenow explained. By referring to FIGS. 14 and 15, a disc cartridge 60 isfirst explained. The disc cartridge 60 has a toroidal rib 61a on theinner peripheral portion of an optical disc 61 where no informationsignals are recorded. A main cartridge body portion 63 has a discinsertion/takeout aperture 83 of substantially the same shape as thecross-sectional shape of the optical disc 61. The portions or componentssimilar to those used in common with those of the disc cartridge 10shown in FIGS. 9 to 11 are denoted by the same reference numerals andthe description therefor is not made.

Similarly to the disc cartridge 10, shown in FIGS. 9 to 11, the disccartridge 60 has a main cartridge body portion 64 formed by combining anupper cartridge half 62 and a lower cartridge half 63 each of which issubstantially in the shape of a saucer of shallow depth. The opticaldisc 61, such as a write-once optical disc or a magneto-optical disc, isrotatably accommodated within the main cartridge body portion 64. Theshutter 16 is slidably mounted on the front side of the main cartridgebody portion 64. The back side of the main cartridge body portion 64 isformed with a disc insertion/takeout aperture 83 for use to insert ortake out the optical disc 61. The upper and lower cartridge halves 62,63 are configured similarly to the cartridge halves 12, 13 of the disccartridge 10 shown in FIGS. 9 to 11.

The optical disc 61, accommodated within the disc cartridge 60, isconstituted by a sole disc substrate 61b, on one major surface of whichan information signal area is formed. This disc substrate 61b has acentrally arranged inner rim holding portion 61c, in which noinformation signals are recorded, a recording area 61d radiallyoutwardly of the inner rim holding portion 61c, in which to recordinformation signals, and an outer rim side non-recording area 61eradially outwardly of the recording area 61d, in which no informationsignals are recorded. The optical disc 61 is formed with an upstandingtoroidal rib 61a extending along an outer edge of the inner rim holdingportion 61c on the signal-recording major surface, that is, therecording and/or reproducing surface. Thus the disc has a cross-sectionof a rectangle with a central raised quadrangular portion.

The inner surface of the main cartridge body portion 64 is formed withan outer rim side disc housing wall section 78 and an inner rim sidedisc housing wall section 79. The outer rim side disc housing wallsection 78 is made up of plural arcuate wall sections lying on the samecircumference of a circle. On the other hand, the inner rim side dischousing wall section 79 is formed on the inner surface of the uppercartridge half 62 which is in register with the outer rim of theupstanding toroidal rib 61a when the optical disc 61 is accommodated inthe main cartridge body portion 64. The outer rim side disc housing wallsection 78 is slightly larger than the outer diameter of the opticaldisc 61 and slightly thicker than the thickness of the optical disc 61.The inner rim side disc housing wall section 79 has a height slightlylarger than the height of the rib 61a. When the upper and lowercartridge halves 62, 63 are combined together, the disc housing wallsections 78, 79 are abutted to each other for delimiting a disc housingsection 80 having the cross-section of a rectangle with a central raisedquadrangular portion. The disc housing section 80 limits the amount ofmovement in the main cartridge body portion 64 of the optical disc 61housed therein.

The side of the main cartridge body portion 64 opposite to its frontside carrying the shutter 16 is formed with a disc insertion/takeoutaperture 83. When the disc cartridge 60 is out of use, that is, when thedisc cartridge 60 is not loaded on the recording and/or reproducingapparatus, the disc insertion/takeout aperture 83 is closed by the lid40 mounted for opening/closure on the rear side of the main cartridgebody portion 64.

On the portions of the disc insertion/ejection aperture 83 towards theupper cartridge half 62 in register with the inner rim holding portion61c and the recording area 61d are formed retention portions 41. By theprovision of the retention portions 41, the disc insertion/ejectionaperture 83 is formed so as to be larger in size than thecross-sectional area of the optical disc 1 as a whole and is shaped as arectangle raised at a center portion. The disc insertion/ejectionaperture 83 is made up of a first opening 83a delimited by the retentionportions 41 in register with the inner rim holding portion 61C of theoptical disc 1 and having the size of the long side slightly larger thanthe diameter of the inner rim holding portion 61C and the size of theshort side slightly larger than the height of the rib 61a, and a secondopening 83b having the size of the long side slightly larger than thediameter of the disc substrate 61b and the size of the short sideslightly larger than the thickness of the disc substrate 61b.

The disc insertion/ejection aperture 83, constructed as described above,is kept in communication with the inside of the disc housing section 80of the main cartridge body portion 64. This prevents the optical disc 61from being inserted in a mistaken manner into the disc housing section80 via the disc insertion/ejection aperture 83. When inserting theoptical disc 61 into the disc housing section 80 of the disc cartridge60, such insertion of the optical disc 61 is enabled only when theoptical disc is inserted via the disc insertion/ejection aperture 83with the inner rim holding portion 61C of the optical disc 61 inalignment with the first aperture 83a and with the substrate 61b inalignment with the second aperture 83b. Conversely, should the opticaldisc 61 be inserted into the disc insertion/ejection aperture in thereversed front-reverse side position with respect to the position fornormal insertion, that is with the disc substrate 61b in alignment withthe first aperture 83a and with the inner rim holding portion 61c inalignment with the second aperture 83b, insertion of the optical disc 61is rejected.

The optical disc housed within the disc cartridge 60 can be exchangedwith a new one when the disc cartridge is not in use, as in the case ofthe disc cartridge 60 shown in FIGS. 9 to 11. In this case, with the lid40 of the disc cartridge 60 opened and with the disc insertion/takeoutaperture 83 facing to outside, the disc cartridge is tilted, with theaperture 83 facing downwards. The optical disc 61 can then be slid andtaken outwards. For accommodating the optical disc 61 in the maincartridge body portion 64, the inner rim holding portion 61C of theoptical disc 61 is set towards the first aperture 83a, while the discsubstrate 61b is set towards the second aperture 83b, with the lid 40 inthe closed state. The optical disc 1 is inserted in this state via thedisc insertion/takeout aperture 83 into the main cartridge body portion64. Since the disc insertion/ejection aperture 83 is formed so as to belarger in size than the cross-sectional area of the optical disc 1 as awhole and is opened in the shape of a rectangle stepped at each upperedge, in register with the inner rim holding portion 61C of the opticaldisc 1, there is no risk of the optical disc 1 being insertedupside-down.

Therefore, with the present disc cartridge 60, there is no risk of theuser inadvertently inserting the optical disc 61 into the main cartridgebody portion 64, with the recording and/or reproducing side not desiredto be recorded or reproduced set in the recording and/or reproducingposition, while there is also no risk of inadvertent erasure of thedesired information signals recorded on the optical disc 1.

In the above-described disc cartridge 60, it is assumed that the dischousing section 80 formed in the main cartridge body portion 64 is inthe shape of a rectangle stepped at each upper edge, similar to theshape of the disc insertion/takeout aperture 83. It should however benoted that the disc housing wall sections 78, 79 of the upper and lowercartridge halves 62, 63 may also be slightly larger than the outsidediameter of the disc substrate 61b, with the height of the disc housingwall sections 78, 79 being the sum of the thickness of the discsubstrate 61b and the height of the rib 61b, for constituting a dischousing section with a rectangular cross-section.

An optical disc and a disc cartridge according to a fourth embodiment ofthe present invention will now be explained. First, a disc cartridge 90according to the fourth embodiment is explained by referring to FIGS. 16and 17. For inserting or taking out an optical disc 91 having a beveledouter rim, the present disc cartridge 90 has a main cartridge bodyportion 92 formed with a disc insertion/takeout aperture 93 of the samecross-sectional shape as that of the optical disc 91. The portions andcomponents used in common with those of the disc cartridge 10 shown inFIGS. 9 and 10 are denoted by the same reference numerals and thecorresponding description is omitted for simplicity.

The disc cartridge 90 has a main cartridge body portion 94 made up of anupper cartridge half 92 and a lower cartridge half 93 which, similarlyto the upper and lower cartridge halves 12, 13 of the disc cartridge 10shown in FIGS. 9 to 11, are shaped substantially as saucers of shallowdepth. The optical disc 91, such as a write-once optical disc or amagneto-optical disc, is rotatably accommodated within the maincartridge body portion 94. The shutter 16 is slidably mounted on themain cartridge body portion 94. The back side of the main cartridge bodyportion 94 is formed with a disc insertion/takeout aperture 95 via whichto inset or take out the optical disc 91.

The optical disc 91, accommodated within the disc cartridge 90, isconstituted by a sole disc substrate 101, on one major surface of whichan information recording area is formed. This disc substrate 101 has acentrally arranged inner rim holding portion 102, in which noinformation signals are recorded, a recording area 103 radiallyoutwardly of the inner rim holding portion 102, in which to recordinformation signals, and an outer rim side non-recording area 104radially outwardly of the recording area 103, in which no informationsignals are recorded. The optical disc 91, constructed as describedabove, has its information signal recording major surface, that is therecording and/or reproducing surface, smaller in outer diameter than theopposite side major surface where no information signals are recorded,such that the outer rim of the optical disc 91 presents a beveledsurface, with the optical disc 91 being substantially frusto-conical incross-section.

On the upper cartridge half 92 or on the lower cartridge half 93 isformed a disc housing wall section 110 constituted by plural arcuatewall sections lying on the same circumference of a circle. The dischousing wall section 110 is formed as an inclined wall section which isin meeting with the outer shape of the optical disc 91 and slightlylarger than the outer diameter of the optical disc 91. When the upperand lower cartridge halves 92, 93 are combined together, the dischousing wall section 110 delimits therein a disc housing section 111.Thus, the disc housing section 111 limits the amount of movement of theoptical disc 91 housed within the main cartridge body portion 94.

The side of the main cartridge body portion 94 opposite to its frontside carrying the shutter 16 is formed with a disc insertion/takeoutaperture 95. When the disc cartridge 90 is not in use, that is when thedisc cartridge 90 is not loaded on the disc recording and/or reproducingapparatus, the disc insertion/takeout aperture 95 is closed by the lid40 mounted for opening/closure on the rear side of the main cartridgebody portion 94.

The disc insertion/takeout aperture 95 has retention portions 113 onboth lateral side ends of the upper cartridge half 92 so that it has asubstantially frusto-conical shape corresponding to the cross-sectionalshape of the optical disc 91. These retention portions 113 are formed asribs on both lateral side ends of the upper cartridge half 92. This discinsertion/takeout aperture 95 has the size of the long side on the sideof the upper half cartridge 92 slightly larger than the diameter of themajor surface of the disc 91 corresponding to its recording and/orreproducing surface and the size of the long side on the side of thelower half cartridge 93 slightly larger than the size of the oppositeside major surface of the optical disc 91, with the size along theheight of the aperture being slightly larger than the thickness of theoptical disc 91.

The disc insertion/ejection aperture 95, constructed as described above,is in communication with the inside of the disc housing section 80 ofthe main cartridge body portion 111. This prevents the optical disc 91from being inserted in a mistaken manner into the disc housing section111 via the disc insertion/ejection aperture 95. When inserting theoptical disc 91 into the disc housing section 111, such insertion of theoptical disc 91 is enabled only when the optical disc is inserted viathe disc insertion/ejection aperture 95 with the side of the recordingand/or reproducing major surface of the optical disc 91 being settowards the upper cartridge 92 of the disc insertion/ejection aperture95 and with the side of the opposite major surface of the optical disc91 being set towards the lower cartridge half 93. Conversely, should theoptical disc 91 be inserted into the disc insertion/ejection aperture inthe reversed front-reverse side position reversed from the position fornormal insertion, that is, with the side of the recording and/orreproducing major surface of the optical disc 91 being set towards thelower cartridge 92 of the disc insertion/ejection aperture 95 and withthe side of the opposite major surface of the optical disc 91 being settowards the upper cartridge half 93, the optical disc 91 cannot beinserted into the disc housing section 111.

The optical disc housed within the disc cartridge 90 can be exchangedwith a new one when the disc cartridge is not in use, that is, when thedisc cartridge is not loaded on the recording and/or reproducingapparatus. In this case, with the lid 40 opened and with the discinsertion/takeout aperture 95 facing to the outside, the disc cartridgeis tilted, with the aperture 95 facing downwards. The optical disc 61can then be slid and taken outwards. For accommodating the optical disc91 in the main cartridge body portion 94, the recording and/orreproducing major surface of the optical disc 61 is set towards theupper cartridge half side of the disc insertion/takeout aperture 95,while the opposite side major surface of the disc is set towards thelower cartridge half side of the second aperture 83b, with the lid 40closed. The optical disc 1 is inserted in this state via the discinsertion/takeout aperture 95 into the main cartridge body portion 94.Since the disc insertion/ejection aperture 95 is formed so as to belarger in size than the cross-sectional area of the optical disc 91 as awhole and is opened in the frusto-conical shape, there is no risk of theoptical disc 1 being inserted upside-down. Therefore, with the presentdisc cartridge 90, there is no risk of the user inadvertently insertingthe optical disc 91 into the main cartridge body portion 94, with therecording and/or reproducing side not desired to be recorded orreproduced set in the recording and/or reproducing position, while thereis also no risk of inadvertent erasure of the desired informationsignals recorded on the optical disc 1.

In the above-described disc cartridge 90, it is assumed that the dischousing section 111 formed in the main cartridge body portion 94 is inthe frusto-conical shape similar to the shape of the discinsertion/takeout aperture 83. It should however be noted that the dischousing section 111 may also be of rectangular cross-section, with thesize of the disc housing wall section 110 of the upper cartridge half 92and the lower cartridge half 93 slightly larger than the outer dimensionof the optical disc 91 and with the height of the housing wall section110 slightly larger than the thickness of the optical disc 91,.

An optical disc and a disc cartridge according to a fifth embodiment ofthe present invention will now be explained. First, a disc cartridge 120according to the fifth embodiment is explained by referring to FIGS. 18to 20. In the following description, it is assumed that the optical disc2 of the second embodiment is accommodated in the disc cartridge 120.

The present disc cartridge 120 is made up of a main cartridge bodyportion 121 in the shape of a box of a thin thickness as a whole andhaving one of the major surfaces thereof opened, and a lid 122 forclosing the opened major surface of the main cartridge body portion 121.The optical disc 2 can be inserted into and remote from the disccartridge 120 by opening/closing the lid 122. The optical disc 2 in thiscase is a recordable optical disc capable of recording informationsignals.

The main cartridge body portion 121 is formed of a synthetic resin ofhigh moldability and sufficient mechanical strength, such as ABS resin,substantially in the shape of a box of a reduced thickness, as shown inFIG. 18. In a mid portion of a major surface 140 of the main cartridgebody portion 121 is formed a circular recess operating as a disc housingsection 141 for accommodating the optical disc 2.

The disc housing section 141 is formed so as to be slightly larger thanthe outer dimension of the optical disc 2. On the rim of the dischousing section 141 is formed a toroidal rib-shaped retention portion142. The retention portion 142 is step-shaped such that a firstupstanding wall section 144 from a bottom surface 143 of the dischousing section 141 is of a height slightly larger than the thickness ofthe disc substrate 24. In continuation to the first upstanding wallsection 144 is formed a setting surface 145 parallel to the bottomsurface 143. In continuation to the setting surface 145 is formed asecond upstanding wall section 146. The retention portion 142 is formedin meeting with a step 2C of the optical disc 2. The disc housingsection 141 limits the amount of movement of the optical disc 2 housedwithin the main cartridge body portion 121.

The bottom surface 143 of the disc housing section 141 is formed with awindow 148 extending from a mid portion towards an outer side of themain cartridge body portion 121 fitted with the lid 122. This window 148is made up of a disc table intrusion opening 148a corresponding in shapeto the disc table provided in the recording and/or reproducing apparatuswhen the disc cartridge 120 is loaded on the recording and/orreproducing apparatus, and a rectangular-shaped recording and/orreproducing opening 148b for exposing to outside a portion of at leastthe recording area S of the optical disc 2 across the inner and outerrims thereof from the disc table intrusion opening 148a towards theouter side of the main cartridge body portion 121 fitted with the lid122.

On a rim of the disc table intrusion opening 148a is formed a riboperating as a setting surface 151 on which the optical disc 2 is setwhen the disc cartridge 120 is not in use. That is, when the disccartridge 120 is not in use, the inner rim holding portion of the discsubstrate 2A is abutted against the setting surface 151.

In register with this window 148 is mounted a shutter configured forbeing opened on loading the disc cartridge 120 on the recording and/orreproducing apparatus and for being closed during non-use of the disccartridge 120 for preventing intrusion of dust and dirt into the dischousing section 141 and deposition thereof on the optical disc 2 housedtherein and for preventing the user's hand or finger's from touching therecording area S of the optical disc 2.

The lid 122 is pivotally mounted for opening/closure on a rear wallsurface section 154 constituting an outer peripheral wall section of themain cartridge body portion 121. The lid 122 is molded from, forexample, a transparent synthetic resin material, and is fitted in anrecess 155 formed in a major surface of the main cartridge body portion121. The inner surface of the lid 122 facing the recess 155 is providedwith a disc clamper 156 facing the disc table intrusion opening 148a.

The disc clamper 156 includes an outer peripheral rib 157 supporting theinner rim holding portion of the optical disc 2, an inner peripheral rib158 fitted in a center aperture 2F of the optical disc 2, and a chuckplate 159 loosely fitted in the outer peripheral rib 157 and the innerperipheral rib 158. The chuck plate 159 clamps the inner rim holdingportion of the optical disc 2 along with the disc table intruded viadisc table intrusion opening 148a. The chuck plate 159 is formed as adisc of synthetic resin material having enclosed therein a magneticmetal plate for enabling magnetic chucking by a magnet mounted on thedisc table.

On the inner surface of the lid 122 is protuberantly formed a rib 160 inregister with the outer peripheral non-recording area of the opticaldisc 2. The rib 160 limits vertical vibrations of the optical disc 2 inthe closed state of the lid 122.

When the above-described disc cartridge 120, having enclosed therein theoptical disc 2, is loaded on the recording and/or reproducing apparatus,the disc table on the side of the recording and/or reproducing apparatusis intruded into the disc table intrusion opening 148a for clamping theoptical disc 2 along with the disc damper 156 on the lid 122 forrotationally driving the optical disc 2.

The optical disc housed within the disc cartridge 120 can be exchangedwith a new one when the disc cartridge is not in use, that is when thedisc cartridge is not loaded on the recording and/or reproducingapparatus. In this case, the optical disc 2 can be exchanged with thelid 122 in an opened state.

For accommodating the optical disc 2 in the main cartridge body portion121, the optical disc is accommodated in the disc housing section 141,with the disc substrate 2A of the optical disc 2 facing downwards, thatis, towards the bottom surface 143 of the disc housing section 141 ofthe cartridge main body portion 121, with the lid 122 remaining closed,as shown in FIG. 19. At this time, the disc housing section 141 isengaged with the retention portion 142 in register with the step 2C ofthe optical disc 2. In this case, the lid 122 is closed by beingpositively fitted in the recess 155.

Conversely, should the optical disc 2 be accommodated within the dischousing section 141 with the disc substrate 2B of the optical disc 2directed downwards, that is, towards the bottom surface 143 of the dischousing section 141 of the main cartridge body portion 121, as shown inFIG. 20, the disc substrate 2B is set on the setting surface 145 withoutthe step 2C of the optical disc 2 becoming engaged with the retentionportion 142. Thus, the disc substrate 2A is protruded via the recess 155of the main cartridge body portion 121, without the lid 122 becomingclosed.

With the above-described disc cartridge 120, there is no risk of theoptical disc 2 being erroneously inserted in the upside-down position.Therefore, with the present disc cartridge 120, there is no risk of theuser inadvertently inserting the optical disc 120 into the maincartridge body portion 121, with the recording and/or reproducing sidenot desired to be recorded or reproduced set in the recording and/orreproducing position, while there is also no risk of inadvertent erasureof the desired information signals recorded on the optical disc 2.

A sixth embodiment of the disc cartridge is now explained. A disccartridge 260 of the sixth embodiment includes a mistaken recordinginhibiting mechanism 263 mounted on a lid 262 closing a discinsertion/takeout aperture 261. The portions or components used incommon with the disc cartridge 10 are denoted by the same referencenumerals and the corresponding description is omitted for simplicity.

Referring to FIG. 21, the rear lateral side of the main cartridgeportion 14 has a disc insertion/takeout aperture 261 via which isinserted an optical disc 1 explained with reference to FIGS. 4 and 5.The disc insertion/takeout aperture 261 has a first aperture portion261a having the size of the long side slightly larger than the diameterof the lesser-diameter disc substrate 1B and the size of the short sideslightly larger than the thickness of the disc substrate 1B, a secondaperture portion 261b having the size of the long side slightly largerthan the diameter of the larger-diameter disc substrate 1A and the sizeof the short side slightly larger than the thickness of the discsubstrate 1A, and a third aperture portion 261c configured similarly tothe first aperture portion 261a. The optical disc 1 having thecross-sectional shape of a rectangle having a raised quadrangular centerportion can be accommodated via the disc-insertion/takeout aperture 261with the disc substrate 1B directed upwards or with the disc substrate1A directed upwards.

The lid 262 closing the disc-insertion/takeout aperture 261 has a mainportion 275 closing the disc-insertion/takeout aperture 261, a hingeformed at an end of the main portion 275 and a retention piece 276formed at the opposite end of the main portion 275.

The main portion 275 has a closing surface 277 on its side facing thedisc insertion/takeout aperture 261. The closing surface 277 is formedon the same arcuate surface as the lateral side edge of the opticaldisc 1. When the lid 262 has closed the disc-insertion/takeout aperture261, the lid defines the disc housing section 20 along with the innersurfaces of the cartridge halves 12, 13. On the major surface 278 of themain portion 275 is mounted the mistaken recording inhibiting mechanism263. When the lid 262 has closed the disc-insertion/takeout aperture261, the main portion 275 is flush with the major surface and thelateral side of the main cartridge body portion 14. On the opposite endof the main portion 275, the retention piece 276 is formed integrallywith the main portion 275. A retention piece 279 is formed at the distalend of the retention piece 276.

The above-described lid 262, when closing the disc-insertion/takeoutaperture 261, is engaged with a protrusion, not shown, formed at theopposite end of the disc insertion/takeout aperture 261 of the maincartridge body portion 14, so that the lid 262 is not accidentallyopened by vibrations produced during transport of the disc cartridge260. When the lid 262 opens the disc-insertion/takeout aperture 261, theretention piece 276 becomes disengaged from the protrusion of the maincartridge body portion 14 as a result of the opening movement.

The mistaken recording inhibiting mechanism 263 is made up of a mistakenrecording inhibiting member 281, mounted on the lid 262, an opening 282formed in the major surface 278 of the lid 262 for exposing the mistakenrecording inhibiting member 281 to outside, and a control opening 283formed in the upper cartridge half 12.

The mistaken recording inhibiting member 281 has an actuating portion284 and a retention portions 285 which is formed on both sides of theactuating portion 284. The retention portion 285 has a cut-out 286extending in the direction of thickness at a junction area to theactuating portion 284.

The opening 282 and the control opening 283 are formed as elongatedopenings extending along the lateral side of the main cartridge portion14 in which is formed the disc insertion/takeout aperture 261. Theseopenings 282, 283 permit the actuating portion 284 of the mistakenrecording inhibiting member 281 to be exposed to the outside, whilepermitting the mistaken recording inhibiting member 281 to be slidtherein.

With the above-described mistaken recording inhibiting mechanism 263, ifthe lid 262 closes the disc insertion/takeout aperture 261, theactuating portion 284 is exposed to the outside via control opening 283.Therefore, the lid 262 is locked by the mistaken recording inhibitingmember 281 against actuation in the opening direction. When the disccartridge 260 is loaded on the recording and/or reproducing apparatus,the mistaken recording inhibiting member 281 inhibits intrusion of adetection portion of the mistaken recording detection means, not shown,provided on the recording and/or reproducing apparatus, thus inhibitingwriting of new information signals on the optical disc 1.

If the lid 262 is actuated in the opening direction, first the retentionportion 285 of the mistaken recording inhibiting member 281 is removed.Since the retention portion 285 is formed with the actuating portion 284via the cut-out 286, it can be easily removed by thrusting the actuatingportion 284 from above. Since the retention portion 285 is removed fromthe openings 282, 283, it becomes possible for the mistaken recordinginhibiting member 281 to unlock the lid 262 to enable the opening of thelid 262.

If the disc cartridge 260, with the mistaken recording inhibiting member281 thus constructed, is loaded on the recording and/or reproducingapparatus, the detection portion of the mistaken recording detectionmeans provided on the apparatus is intruded into the openings 282, 283to permit writing of new information signals on the optical disc 1.

Thus, if the optical disc 1 is not taken out of the disc cartridge 260even once, it becomes possible for the user to recognize that writing ofnew information signals is inhibited. If the user takes out the opticaldisc 1 out of the disc cartridge 260 even once, the user can recognizethat writing of new information signals has been enabled.

A seventh embodiment of the disc cartridge is now explained.

In a disc cartridge 290 of the seventh embodiment, an auxiliary memberof the mistaken recording inhibiting mechanism 291 is mounted on a lid292 adapted for closing the disc insertion/takeout aperture 17, as shownin FIG. 22. The present embodiment is otherwise the same as the disccartridge 10 shown in FIGS. 9 to 11.

The lid 292 closing the disc insertion/takeout aperture has a mainportion 293 for closing the disc insertion/takeout aperture 17, a hinge,not shown, formed at an end of the main portion 293, and a retentionpiece 294 formed at the opposite end of the main portion 293.

The side of the main portion 293 facing the disc insertion/takeoutaperture is formed with a closing surface 295. The closing surface 295is formed to have the same arcuate surface as the lateral side edge ofthe optical disc 1. When the lid 292 has closed the discinsertion/takeout aperture, the lid forms a part of the disc housingsection 20. On the major surface 296 of the main portion 293 is arrangedthe mistaken recording inhibiting mechanism 291. When the lid 292 hasclosed the disc insertion/takeout aperture, the main portion 293 isflush with the major surface and the lateral side of the main cartridgebody portion 14. The retention piece 294, formed at the opposite end ofthe of the main portion 293, is formed integrally with the main portion293, and has at its distal end a retention portion 297.

When the above-described lid 292 has closed the disc insertion/takeoutaperture, the retention portion 297 is engaged with a protrusion, notshown, formed at the opposite end of the disc insertion/takeout apertureof the main cartridge body portion 14, for preventing the lid from beingopened even under vibrations produced during transport of the disccartridge 290. When the disc insertion/takeout aperture is opened, theretention piece 294 is unlocked to permit opening of the lid 292.

The mistaken recording inhibiting mechanism 291 is made up of a mistakenrecording inhibiting member 301, mounted on the lid 292, an opening 302formed in the major surface 296 of the lid 292 for exposing the mistakenrecording inhibiting member 301 to outside, a connecting piece 303 forconnecting the mistaken recording inhibiting member 301 to the opening302 and a control opening, not shown, formed in the upper cartridge half12. The connecting piece 303 is formed as a thin sheet so as to bedestroyed on being thrust by the mistaken recording inhibiting member301.

With the above-described mistaken recording inhibiting mechanism 291, ifthe lid 292 has closed the disc insertion/takeout aperture, the mistakenrecording inhibiting member 301 is exposed to outside via an opening,not shown, in the upper cartridge half 12. Therefore, the lid 292 islocked by the mistaken recording inhibiting member 301 against beingactuated in the opening direction. With the mistaken recordinginhibiting member 301, the detection portion of the mistaken recordingdetection means of the recording and/or reproducing apparatus isprohibited from being intruded if the disc cartridge 290 is loaded onthe recording and/or reproducing apparatus, thus inhibiting writing ofnew information signals on the optical disc 1.

When actuating the lid 292 in the opening direction, the connectingpiece 303 of the mistaken recording inhibiting member 301 is firstdestroyed. The connecting piece 303 is destroyed by the inhibitingmember 301 being thrust from above. Since the connecting piece 303 isdestroyed, the mistaken recording inhibiting member 301 is removed fromthe opening 302. The result is that the lid 292 becomes unlocked andhence the lid 292 can be opened.

If the disc cartridge 290, from which the mistaken recording inhibitingmember 301 has been cut off, is loaded on the recording and/orreproducing apparatus, the detection portion of the mistaken recordingdetection means of the recording and/or reproducing apparatus can beintruded into the opening 302 and the control opening, not shown, of theupper cartridge half 12, so that new information signals can be writtenon the optical disc 1. Thus, if the optical disc 1 has never been takenout of the disc cartridge 290, the user can recognize that writing ofnew information signals is inhibited. Once the user has taken out theoptical disc 1 from the disc cartridge 290, he or she can recognize thatwriting of new information signals has been enabled.

With the above-described lid 292, an auxiliary member 305 of themistaken recording inhibiting member 301 is provided as one with themajor surface 296 of the lid. This auxiliary member 305 is mounted inthe opening 302 once the mistaken recording inhibiting member 301 hasbeen removed. The auxiliary member 305 is made up of an operating member306 and an elastic piece 307 protruded from a lateral edge of theoperating member 306, and is connected to the main portion 293 by aconnection piece 308. The auxiliary member 305 is of the same outershape as the mistaken recording inhibiting member 301. The elastic piece307 is protruded from the rim of the mistaken recording inhibitingmember 301 so as to be slightly larger in size than the opening 302.

When mounted in the opening 302, the auxiliary member 305 is first cutoff from the connection piece 308. At this time, the auxiliary member305 is cut off by warping upwards or downwards. The auxiliary member305, thus cut off, is mounted by being pushed into the opening 302 byflexure of the elastic piece 307. The elastic piece 307 is slightlylarger in size than the opening 302, so that, by thrusting the auxiliarymember 305, the elastic piece 307 is elastically displaced so as to beintruded into the opening 302. Since the elastic piece 307 is slightlylarger in size than the opening 302 and is engaged with the peripheralwall of the opening 302, there is no risk of inadvertent removal of theelastic piece 307 from the opening 302 during transport of the disccartridge 290. By using the auxiliary member 305 in this manner, itbecomes possible to re-use the disc cartridge 290.

An eighth embodiment of the disc cartridge is now explained. A disccartridge 320 of the eighth embodiment includes a mistaken recordinginhibiting mechanism 322 in the vicinity of a disc insertion/takeoutaperture 321 of the main cartridge body portion 14, as shown in FIG. 23.The portions or components used in common with the disc cartridge 10 aredenoted by the same reference numerals and the corresponding descriptionis not made for simplicity.

Into the disc insertion/takeout aperture 321 formed in the rear lateralside of the main cartridge body portion 14 is introduced the opticaldisc 1 shown in FIGS. 4 and 5. The disc insertion/takeout aperture 321is rectangular in shape and dimensioned so that its long side isslightly larger than the diameter of the larger-diameter disc substrate1A and its short side is slightly larger than the sum of the thicknessesof the disc substrates 1A and 1B. The disc insertion/takeout aperture321 is configured so that the optical disc 1 having the cross-section ofa rectangle stepped at both lateral edges may be inserted into the dischousing section without regard to whether the disc substrate 1B isdirected upwards or the disc substrate 1A is directed upwards.

The disc insertion/takeout aperture 321 is opened or closed by the lid40 of the disc cartridge 1 shown in FIGS. 9 to 11.

The mistaken recording inhibiting mechanism 322 is made up of aretention piece 325 limiting the position of the optical disc 1, amistaken recording inhibiting member 326 mounted as one with theretention piece 325 and a control opening 327 formed in the upper andlower cartridge halves 12, 13.

The retention piece 325 is substantially elliptical in shape and has itsone end fulcrumed by a pivot 330 formed on the upper and lower cartridgehalves 12, 13 so that the retention piece will be turned in thedirections indicated by arrows C and D in FIG. 23.

The retention piece 325 has at its opposite end a hole 328 in themistaken recording inhibiting member 326 is mounted by plural connectingpieces 329 as one with the retention piece 325. A recessed engagementportion 331 is formed in the upper surface of the mistaken recordinginhibiting member 326. The mistaken recording inhibiting member 326 hasits both ends exposed to outside via control openings 327 formed at thecorner of the upper and lower cartridge halves 12, 13 in the vicinity ofthe disc insertion/takeout aperture 321. The mistaken recordinginhibiting member 326 can be cut off by inserting and rotating a femaledriver in the engagement portion 331. Once the mistaken recordinginhibiting member 326 is cut off, no information signals can be recordedon an optical disc contained in the disc cartridge even if the opticaldisc is exchanged.

The control opening 327 is formed in an arcuate shape with the long sideof the arc extending parallel to the lateral side of the main cartridgebody portion 14 in which the disc insertion/takeout aperture 321 isformed. The mistaken recording inhibiting member 326 is actuated in thedirection indicated by arrows C and D in FIG. 23 along the controlopening 327 for rotating the retention piece 325.

The above-described mistaken recording inhibiting mechanism 322 being inthe first position, indicated V in FIG. 23, indicates that the retentionpiece 325 locks the lateral side edge of the disc 1, and that themistaken recording inhibiting member 326 inhibits writing of newinformation signals. The above-described mistaken recording inhibitingmechanism 322 being in the second position, indicated W in FIG. 23, as aresult of the sliding movement of the mistaken recording inhibitingmember 326, indicates that the locked state of the lateral side edge ofthe disc 1 by the retention piece 325 is released to enable the disc 1to be taken out of the disc insertion/takeout aperture 321, with themistaken recording inhibiting member 326 permitting writing of newinformation signals. If the mistaken recording inhibiting member 326 hasbeen cut off as described above, the mistaken recording detection meanson the recording and/or reproducing apparatus deems that recording isdisabled. Thus, even in case of disc exchange, no information signalscan be inadvertently recorded on an exchanged disc.

With the above-described disc cartridge 320, if the disc 1 has beentaken out of the disc cartridge 320, the mistaken recording inhibitingmember 326 of the mistaken recording inhibiting mechanism 322 issimultaneously brought to the second position indicated W in FIG. 23,the user can recognize that the writing on the disc 1 is enabled.

On the other hand, if the disc 1 is housed within the disc cartridge320, the mistaken recording inhibiting member 326 of the mistakenrecording inhibiting mechanism 322 is brought to the first positionindicated V in FIG. 23. Thus the user can recognize that the writing onthe disc 1 is now disabled.

The present invention may be modified in many ways without departingfrom the spirit and purpose of the invention.

What is claimed is:
 1. A disc cartridge accommodating a disc comprisedof two disc substrates bonded together, said disc being non-symmetricalin cross-section about a bonding center line, comprising:a maincartridge body portion forming a disc housing and having an aperture viawhich to insert and take out said disc to and from said disc housing andfurther having two rib-like retainers extending from said aperture intosaid disc housing, so that said aperture is formed to have a shapesubstantially identical to the non-symmetrical cross-section of the discand so that said aperture is configured for accommodating said disc onlyin one orientation corresponding to a state of permitting recordingand/or reproduction of said disc; and an opening/closure mechanism foropening/closing said aperture, including a takeout inhibiting mechanismspecifying whether recording on said disc is possible, said takeoutinhibiting mechanism inhibiting takeout of said disc from said maincartridge body portion and including a discriminating member forspecifying a state of inhibiting recording on the disc upon being movedto a first position of being exposed to the outside through a controlopening formed in said main cartridge body portion and for specifying astate of possible recording on the disc upon being moved to a secondposition exposed to the outside through said control opening, andwherein said inhibiting mechanism, when moved to said first position isengaged with and retains said disc.
 2. The disc cartridge as claimed inclaim 1, wherein said aperture has a shape corresponding to across-sectional shape of said disc so as to permit insertion andejection of said disc only in said state of permitting recording and/orreproduction of said disc.
 3. The disc cartridge as claimed in claim 1,wherein said aperture includes a retention portion adapted for lockingsaid disc when said disc is inserted in a state of not permittingrecording and/or reproduction of the disc.
 4. The disc cartridge asclaimed in claim 1, wherein said aperture is formed in a lateral side ofsaid main cartridge body portion and said opening/closure mechanismincludes an opening/closure member rotatably mounted on said maincartridge body portion for opening/closing said aperture.
 5. A disccartridge accommodating a disc comprised of two disc substrates bondedtogether, said disc being non-symmetrical in cross-section about abonding center line, comprising:a main cartridge body portion forming adisc housing and having an aperture via which to insert and take outsaid disc to and from said disc housing and further having two rib-likeretainers extending from said aperture into said disc housing, so thatsaid aperture has a shape substantially identical to the non-symmetricalcross-section of the disc, whereby said aperture is configured foraccommodating said disc only in one orientation corresponding to a stateof permitting recording and/or reproduction of said disc; and anopening/closure mechanism for opening/closing said aperture, including atakeout inhibiting mechanism specifying whether recording on said discis possible, said takeout inhibiting mechanism, when in a state ofinhibiting recording on the disc, inhibiting takeout of the disc fromsaid main cartridge body portion, and the opening/closing movement ofthe opening/closure mechanism being inhibited when said inhibitingmechanism specifies a state of inhibiting recording on said disc, saidtakeout inhibiting mechanism including a discriminating memberspecifying whether recording on the disc is possible, saiddiscriminating member being mounted for movement between a firstposition specifying the state of inhibiting recording on said disc and asecond position specifying a state of possible recording on said disc,and wherein said main cartridge body includes a discrimination openinginto which said discrimination member is intruded.
 6. A disc cartridgeaccommodating therein a disc non-symmetrical in cross-sectional shaperelative to a center line of the disc in a thickness direction,comprising:a main cartridge body portion forming a disc housing andhaving an aperture via which to insert or take out a disc to and fromsaid disc housing and further having two rib-like retainers extendingfrom said aperture into said disc housing, so that said aperture has ashape substantially identical to the non-symmetrical cross-section ofthe disc, whereby said aperture is formed for accommodating the disconly in one orientation corresponding to a state permitting recordingand/or reproduction of the disc; and an opening/closure mechanism foropening/closing said aperture, including a takeout inhibiting mechanismfor specifying whether recording on the disc is possible and when in thestate of inhibiting recording on the disc for inhibiting takeout of saiddisc from said main cartridge body portion, said takeout inhibitingmechanism including a discriminating member movably mounted on saidopening/closing mechanism for specifying whether recording on the discis possible and being mounted for movement to a first position of beingexposed through a control opening when specifying the state ofinhibiting recording and for movement to a second position of beingexposed through said control opening when specifying the state ofpossible recording, wherein said discriminating member, when moved tosaid first position is engaged with and retains the disc.
 7. The disccartridge as claimed in claim 6, wherein said aperture has a shapecorresponding to a cross-sectional shape of the disc for enablinginsertion or takeout of the disc only in the state permitting recordingand/or reproduction to the disc.
 8. The disc cartridge as claimed inclaim 6, wherein said aperture includes a retention portion for lockingthe disc when inserted in a state of not permitting recording and/orreproduction of the disc.
 9. The disc cartridge as claimed in claim 6,wherein said aperture is formed in a lateral side of said main cartridgebody portion and wherein said opening/closure mechanism includes anopening/closure member rotatably mounted on said main cartridge bodyportion for opening/closing said aperture.
 10. The disc cartridge asclaimed in claim 6, wherein the opening/closing movement of theopening/closure mechanism is inhibited when said takeout inhibitingmechanism specifies the state of inhibiting recording on the disc. 11.The disc cartridge as claimed in claim 10, wherein said discriminatingmember is mounted for movement between a first position specifying thestate of inhibiting recording on the disc and a second positionspecifying the state of possible recording on the disc.
 12. The disccartridge as claimed in claim 11 wherein said main cartridge bodyportion includes a discrimination opening via which said discriminatingmember is intruded.